New wastewater study reveals household chemical may contribute to ‘superbugs’

Posted 22 June 2018

Antibiotic resistance is a global challenge with approximately 700,000 people a year dying from antimicrobial-resistant infections, but a recent wastewater study reveals triclosan – a compound used in more than 2000 personal care products – could be the leading cause of ‘superbugs’.

Triclosan is a non-antibiotic, antimicrobial (NAAM) chemical commonly used in toothpaste and hand wash, and University of Queensland study lead Dr Jianhua Guo said the high level of antibiotic resistance in residential wastewater indicated that this chemical may be a key culprit.

“Wastewater from residential areas has similar or even higher levels of antibiotic resistant bacteria and antibiotic resistance genes compared to hospitals, where you would expect greater antibiotic concentrations,” he said.

“We then wondered whether [NAAM] chemicals such as triclosan can directly induce antibiotic resistance. These chemicals are used in much larger quantities at an everyday level, so you end up with high residual levels in the wider environment, which can induce multi-drug resistance.”

Guo said the revelation is a strong indication that overuse of chemicals other than antibiotics need to be considered when tackling the global antibiotic resistance challenge.

“This discovery provides strong evidence that the triclosan found in personal care products that we use daily is accelerating the spread of antibiotic resistance,” he said.

University of Queensland Advanced Water Management Centre Director Professor Zhiguo Yuan said the discovery should serve as a warning to start re-evaluating the potential impact of such chemicals.

“While the US Food and Drug Administration (FDA) has banned the use of triclosan in antibacterial soap, the previous lack of unequivocal evidence prevented such a policy being adopted in other countries,” Yuan said.

The Australian government Department of Health is aware of the FDA recommendations and is set to review information to see whether any action is required in the Australian context.

Published in Environment International, the study was funded by the Australian Research Council Future Fellowship and the UQ Foundation Research Excellence Awards.